I've installed a q2a plugin (Notification Pro) and after that I've launched a database initialization process required by it.
The db initialization was successful, but on the error_log I noticed this entry :
PHP Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /var/www/question2answer/qa-include/qa-db-install.php:1464) in /var/www/question2answer/qa-include/qa-app-users.php on line 150
Since I've already seen many complaints about this issue on q2a, I begin to think that it's a q2a bug.....
I'm using the default Snow theme, not modified, and I have no BOMs in my files.
The message is clear. A flush of bytes for the http response has already been done.
In fact, you can see at line 1464 of qa-db-install.php :
echo qa_html($text).str_repeat(' ', 1024)."<br><br>\n";
flush();
After that a "session start" seems to be executed :
if (!isset($_SESSION))
session_start();
($_SESSION still not set ?)
This should not happen, right ?
Well, I know I posted an error related to a plugin that is not free, but I think that this error happened so many times also in other situations.
So I decided to share it all the same.
I think that there are some paths in the q2a install process code that lead to this condition.
Bug ?
I think that, if a bug is confirmed, it could have a low priority : the installation process seems to be successful (at least in my case).